Well drilling bit



Aug' 22, 1933- J. H. HOWARD Er AL. 1,923,487

WELL DMLLING BIT Filed Oct. 5, 1931 AVK/460 C. Cof/w70 Patented Aug. 22, 1933 1,923,487 WELL DRILLING BIT John H. Howard, Huntington Park, and Alfred C. Catland; Alhambra, Calif., assignors to Globe Oil Tools Company, Corporation of California Los Nietos, Calif., a

Application october 5, 1931.y serial N. 566,911

2 claims. (o1. 255s1 This invention relates to a well drilling tool of the invention. Fig. 2 is a fragmentary horiand relatesmore particularly to a well bit. It zontal detailed sectional view of the tool illusis a general'object of the present invention to trated in Fig. 1, being a view taken through a provide a well bit involving a practical, effective portion of the body and one of the blades and and improved cutting means.

In the drilling of deep wells, for example, oil wells, earth formations are encountered that are effectively drilled by diamonds or bodies of hard cutting material known as diamond substitutes provided on the drilling tools. It is desirable to mount the bodies of hard cutting material on blades formed of material having relatively low resistance to abrasion so that the tool Will be self-sharpening through use. Most materials 35 having low resistance to abrasion are not very strong and therefore are not well suited for directly carrying the diamond substitutes or bodies of hard cutting material.

An object of the invention is to provide a well bit including cutting means comprising plates of relatively hard material carrying the diamond substitutes and blades of a material having relatively low resistance to abrasion cast on the body of the tool and carrying and backing up the said plates.

Another object of the invention is to provide a Well bit of the character mentioned in which the relatively soft material having low resistance to abrasion is cast directly onto the body of the bit and provides or has integrally formed therewithythe projecting blades carrying the cutting units.

Another object of the inventionis to provide a cutting unit for a well drilling tool consisting of a multiplicity of diamond substitutes or bodies of hard cutting material embedded'or partially embedded in la. plate of steel, hard bronze or the like.

Another object of the invention is to provide a bit of the character mentioned including simple, practical andimproved means for securing or xing the cutting units to the backing up blades of relatively soft material.

Another object of the invention is to provide a well bit of the character mentioned inwhich the cutting units Aare applied to or mounted on the tool after the relatively soft materialis cast on the body of the tool.

w Further objects and features of our invention cutting units. Fig. 3 is a fragmentary horizontal 60 detailed sectional View of another embodiment of the invention.

The cutting means and the manner of mounting the cutting means provided by this invention may be readily embodied in various classes of tools, for example, in Well bits, well reamers, etc.,

f different styles and characters. Throughout the following detailed'disclosure, the invention will be described in two simple forms embodied in Well bits. I t is to be understood that the present invention is not to be construed as limited or restricted to the specific forms or applications about to be described, but is to be taken as in- Icluding any features or modifications that may fall Within the scope of the claims.

'The embodiment of the invention illustrated in Figs. 1 and 2|of the drawingincludes generally, a body 10,` material 11 having relatively low re sistance to abrasion, cast on the body 10 and having a plurality of projecting blades B, cutting units 12and means 13,l for attaching or xing the cutting units 12 to the braces B.

The body 10 is cylindrical in its general conflguration'and is provided in its upper. end portion with a centrallongitudinal uid passage 111. The lower end part of the body 10 is rounded or substantially semi-spherical as illustrated in Fig. 1 of the drawing. A plurality of branch openings 15 are provided in the lower end of the body 10 to communicate with the main fluid passage 14. vA plurality of circumferentially spaced vertical ribs-16 project. from the body 10 through which the operating or icutting' thrusts are transmitteddirectly from the cutting 12A to the body 10, as will be hereinafter described. Inthe specific embodimentv ofthe invention disclosed in the drawing where there are four cutting blades B and cutting units 12, there are four equally spaced ribs 16 provided on the body.4 The ysidesor faces 17 of the ribs thatare forward 100 relative to the direction of rotation of the tool during operation, are at and vertical to-receive the cutting units 12.

In accordance-with the preferred construction,

will be best and more fully understood from the a single body of relatively soft material 11 is 105 following detailed description of typical forms cast directly onto the body 10 and involves or and applications of the invention, throughout provides projecting blades B for carrying "and which description reference will be had tothe backing up the cutting units 12. vThe material. 55 accompanying drawing, in which: 11 may be in the nature of bronze, brass, alumi- 'n Fig. 1 is a perspective view of one vembodiment num or the like. The relatively soft ,material G.'

11 may completely encase the periphery and the lower end of the body 10. If desired or found necessary, the body 10 may be plated or otherwise treated to insure a more perfect bond with the covering material 11. Anchoring means is provided to effectively tie or connect the material to the body 10. A plurality of spaced vertical ribs or tongues 18 are provided on the body 10 to be embedded in the material 11. Fluid discharge openings 19 are formed in the material 11 to communicate with the openings 15 and to discharge the circulation uid downwardly from the lower end of the tool.

The blades B are formed or cast integral with the main body of material l1 and project substantially radially from the body. The blades B are equally spaced about the center of the tool and project downwardly and outwardly from the lower end of the body. The upper ends 20 of the blades are inclined outwardly and downwardly, while the lower ends of the blades are inclined or curved upwardly and inwardly. In accordance with the invention the forward sides or faces 21 of the blades relative to the direction of rotation of the tool are flat and are in radial alignment with the forward faces 1'7 of the ribs 16. The outer and lower ends of the blades B are bevelled rearwardly and inwardly away from the forward faces 21, as clearly illustratedA in Fig. 1 of the drawing. Elongated grooves or slots 23 are provided in the material 11 immediately forward of or in front of the ribs 16. The slots 23 preferably extend the entire lengths of the blades B and extend inwardly to the body 10.

The cutting units 12 are the active or cutting elements of the tool and are mounted on the forward faces 17 of the blades B. There is one cutting unit 12 provided on each blade B and each unit includes a plate 24 and a multiplicity of bodies 25 of hard cutting material. Ihe plates -24 are formed of a relatively hard material such as steel or hard bronze. The plates 24 are shaped so that their upper, lower and outer edges are substantially flush with the corresponding edges of the blades B.` In accordance with the invention, the plates 24 are shaped so that their inner edges evenly engage or abut the rounded lower end portion of the body 10 in the inner ends of the slots 23. The plates 24 are adapted to be arranged against the forward faces 21 of the blades B and passed into the slots23 so that their inner edges are against the body 10. The opposite sides of the plates 24 are preferably flat and parallel as illustrated throughout the drawing.

The diamond substitutes or bodies 25 of hard cutting material may be formed of tungsten carbide or other suitable hard cutting material. A multiplicity of the bodies 25 are embedded or partially embedded in each of the mounting plates 24. In the case illustrated in the drawing, the cutting bodies 25 are rectangular and are partially embedded in the plates 24 so that their outer sides are flush with theforward faces of the plates. It is preferred to mount the bodies 25 in spaced relation and to distribute them across the plates 24. In the form of invention illustrated in the drawing, the bodies of hard cutting material are embedded in the plates 24 in spaced relation and in vertical and substantially horizontal rows: A vertical row of the bodies 25 preferably occurs at the outer edge of each plate 24 while a horizontal row of the bodies 25 preferably occurs at the lower edge of each of the plates. The diamond substitutes or hard bodies 25 may be cast or embedded in the mounting plates 24 in any known or desired manner. It may be found desirable to form the plates 24 of hard bronze in preference to steel, as hard bronz bonds more perfectly with -the diamond substitutes 25 and has a comparatively low melting point, so that the diamond substitutes may be embedded in the plates without being subjected to high temperatures which are usually injurious to hard cutting inserts. It is to be understood that the mounting plates 24 are formed of a material having greater strength than the material 11 and a material that is sulciently strong and rigid to effectively hold the diamond substitutes25.

The means 13 for fixing or attaching the cutting units 12 to the blades B includes a plurality of drive screws 26 for securing each plate 24 to its backing up blade B. The drive screws 26 are adapted to be driven through spaced horizontal openings in the plates 24 and into the blades B. The screws 26 are formed of hardened steel and have coarse heavily pitched threads so that they become firmly fixed in the plates and blades B. Heads 27 are provided on the outer ends of the screws 26 to engage the forward faces of the plates 24. When the drive screws 26 are driven into place, they tightly and permanently attach the cutting units 12 to the blades B.

In the operation of the form of the invention illustrated in Figs. 1 and 2 of the drawing, the

bodies 25 of hard cutting material are mounted* so as to be effective in acting upon the formation. The backing up blades B, in being formed of a relatively soft material are Worn away as the wear on the cutting units 12 progresses, so that the tool always has ample working clearance. The plates 24 are of sufliciently hard rigid material to dependably carry the cutting bodies 25 and so as to withstand the working thrusts and pressures. The blades B effectively back up and support the plates 24 while the ribs 16 engage the rear sides of the plates 24 to transmit the cutting thrusts directly to the body 10. The curved inner edges of the plates 24 engage the body 10 so that the upward working thrusts or pressures are directlytransmitted to the body and do not put undue strains on the screws 26. The diamond substitutes 25, in being embedded in the forward sides of the plates 24 are at all times exposed so as to actively engage the formation. It is to be noted that the invention provides a bit in which the backing up blades B effectively carry and support the cutting units 12, but do not in any way interfere with the proper cutting action of the hard cutting elements 25. As the blades 25 are readily worn away together with the cutting units 12, the tool is self-sharpening. The body 10 may be recovered upon the wearing away of the cutting means so that it mayfbe again utilized. The material 11 may be melted from the body 10 so that the body may be provided with the second covering of soft ma- 1 terial 11 and with the new cutting units 12.

In the form of invention disclosed in Fig. 3 of the drawing, the body 10a, the relatively soft material 11a, and the cutting units'12a are substantially identical with the corresponding elements of the embodiment illustrated in Figs. 1

and 2. The means 13a for attaching the cutting' units 12a to the blades B includes a plurality of spaced studs 30 projecting from the rear side of each plate 24a. The studs 30 extend into spaced openings 31v in the blades B. The openineens? ings 3i entend completely through the hilados B' one; their roer or outer end portions ore tapered or ored outwardly. Nuts 32 ore threoded on the studs 3o to clamp the nietesV 24a against the forword sides oi the lolodes B' ond the ritos loo. The nuts 32 ere irustro-conicel to nt the .tapered openings 3l; The nuts 32 are preernloiy fully countersunir in the openings 3i and ore 'provided et their outer ends with polygonol sockets 33. 'lilhe body lilo ond the relatively soit materiel llo nre relieved in iront oi the ritos 16o to iecilitote the possoge oi the studs 30 into the openings :il and the positioning oi the plot/es Zee ogninst the lolodes ond ribs. The inner edge portions oi the pistes 24o ore seated` in notches 3i immediote- Y ly in iront oi the ribs 16a. it will he reodily on parent how the cutting units 12o moy' he eesily ond quickly mounted on the blades E. The ieetures ond operation oi the embodiment disclosed in 3 are similar genernlly to those oi the shove described form of the invention.` The studs 30 ond the nuts 32 tightly and eectively clamp the cutting units 12a against the blades B' eind the ribs 16o. in this form oi invention, the cutting units y12a moy he replaced ot ony time without replacing the relatively soit materiel llo.

Hoving described only typical preferred iorms of ourinvention, we do not Wish to limit ourselves to the sneoic details set forth, lout wish to reserve to ourselves chonges or voriotions t onweer to those skilled in the ort or ioli lWithin the soope oi the iollowing eloims:

Hoving described our invention, we eleim:

l. fi well drilling tool including o, loody, o. mojecting rib on the body, relatively soft teriol Sii cest on the loody ond having o projecting blade,

the ieee oi seid binde being in' the some plone es the iorword `fece of the rib, there heine` o slot in the materiel ot the forward ieee oi the rile, o, plete of relotively herd materiel arranged ogoinst the ieee oi the hlode ond the iorwerol ieee oi the rito ond extending into the slot to engoge the body, ond means ior ottoching the plete to the hinder. t

2. fi well drilling tool including o loody, o loro jecting rio on the loody, relotively soft materiel oost on the body end having o projecting toledo, the foce oi seid blade being in the. some plone es the forward fece of the rib, these heing n slot in the materiel et the iorword ieee oi the rib, n plete oi relatively hard material orronged signinst the ieee of the blade and the forward ieee oi the iib ond extending into the slot to engage the body, ond means ier ette/ching the plete to the hlnde, bodies of hard cutting materiel embedded in the plete, sind screw ineens for ottoehing the plete to the toledo.

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